Correct Answer: Consumer price index (CPI)

Solution : The correct answer is (a) Consumer price index (CPI).

The consumer price index (CPI) is a measure of the average price level of goods and services consumed by households. It is used to track inflation and estimate changes in the cost of living. The CPI is a macroeconomic indicator because it provides information about the overall price level in an economy. It reflects the changes in prices of a basket of goods and services typically consumed by households, allowing policymakers and economists to assess the rate of inflation and make informed decisions regarding monetary policy, wage adjustments, and economic planning.